A resistive random access memory has two separate resistance states:                a high resistance state (HRS), also called “OFF” state, and        a low resistance state (LRS), also called “ON” state.        
A resistive random access memory comprises first and second electrodes separated by an active zone. A resistive random access memory switches in a reversible manner from the OFF state to the ON state through application of a first threshold voltage between the first and second electrodes, and switches in a reversible manner from the ON state to the OFF state by application of a second threshold voltage between the first and second electrodes. It may thus be used to store binary information.
Resistive random access memories have notably the following advantages:                low threshold voltages required to switch from one state to the other;        long endurance;        low manufacturing costs.        
A major drawback of resistive random access memories is nevertheless the large dispersion of resistances obtained around a mean resistance, from one memory device to another, for a same resistance state. The resistance value of a same resistance state may thus vary by more than an order of magnitude, from one memory device to another. This drawback is particularly critical for the OFF state of resistive random access memories.
The document WO 2014/137943 A2 describes a method for detecting resistance states of resistive memories by means of a detection amplifier. The detection amplifier makes it possible to compare the impedance values of several memories, between each other or compared to a fixed reference. The method described by the document WO 2014/137943 A2 thus makes it possible to evaluate the dispersion of impedance values of a resistance state, but does not make it possible to reduce this dispersion.